1. Field of the Invention
The invention relates generally to doors and door frames and, in particular, to an apparatus for securing a hinged door in a closed position.
2. Description of Related Technology
Typically, exterior doors of residences and commercial buildings are secured in a closed position by a latch mechanism that may include a doorknob latch and/or a dead bolt on one edge of the door and a hinge mechanism on an opposite edge of the door, secured to a door frame. Also typically, these exterior doors open by swinging inwardly about the hinge mechanism into the dwelling or building. One drawback of such an arrangement is that the door can be forcibly opened by prying the door away from the door frame at the latch edge of the door or by forcibly striking the door (e.g., kicking the door) in order to cause the latch mechanism and/or a portion of the door frame that receives the latch mechanism to fail.
Also, when the door is forcibly struck or kicked, fit may bow or bend inward, thereby pulling the doorknob latch and/or the dead bolt away from the door frame. In extreme cases, the door may bow or bend to a sufficient extent to cause the doorknob latch and/or the dead bolt to completely disengage from the portion of the door frame that receives the latch and/or dead bolt.
In many buildings and residences, the door frame is constructed of wood and can fail due to the force applied by kicking or prying the door open. Furthermore, in some door frames, the latch mechanism of the door engages a door jamb, mounted between the door frame and the door, that is weaker still than the door frame. Therefore, there is a need for a simple yet effective device to reinforce a door frame to guard against unauthorized entry.
A number of devices have been developed in order to secure a hinged door against unauthorized entry. Many of these devices include structure to reinforce the door frame or door jamb in a portion of the door frame or door jamb that receives the door latch and the dead bolt.
For example, Hamilton U.S. Pat. No. 5,016,930 (May 21, 1991) discloses a security device for installation in a door frame beneath a strike plate that receives a latch bolt. The security device includes a flat bar disposed vertically within the door frame. Fasteners at either end of the bar pass through the bar in a direction perpendicular to the plane of the door and extend into the door frame, and thereby secure the bar against the door frame. When the door is closed and locked, the bar engages the latch bolt or latch to secure the latch bolt or latch in a receptacle in the door frame.
One disadvantage of existing devices of the type described above is their inability to secure a door from opening if the door is bowed or bent away from the door frame. Also, these devices do not provide any means for strengthening the attachment between the hinges and the door or door frame.